fix: preserve MCP tool metadata across transport

[Q00]

Summary

• return MCP SDK CallToolResult from FastMCP wrappers so MCPToolResult.meta survives the served boundary
• restore SDK result meta in MCPClientAdapter parsing
• cover server and client metadata preservation for interview reasoning surfaces

Original PR blocker coverage

Addresses the MCP interview reasoning transport blocker reported on #1140.

Verification

• uv run --extra mcp pytest tests/unit/mcp/server/test_adapter.py tests/unit/mcp/client/test_adapter.py tests/unit/mcp/tools/test_interview_response_diagnostics.py -q
• uv run ruff check src/ouroboros/mcp/server/adapter.py src/ouroboros/mcp/client/adapter.py tests/unit/mcp/server/test_adapter.py tests/unit/mcp/client/test_adapter.py

[ouroboros-agent]

Review — ouroboros-agent[bot]

Verdict: APPROVE

Metadata

| Field | Value |
|### Recovery Notes
First recoverable review artifact generated from codex analysis log.

---|---|
| PR | #1210 |
| HEAD checked | 261fd0219a91ecf3beb431df56dacdfa59284922 |
| Request ID | req_retry_exhausted_new_timeout_1779693693_1210 |
| Review record | d917bb7a-38f2-4bd7-8a78-824a27134e77 |

What Improved

• Preserves MCP tool-result metadata across both the FastMCP server boundary and the MCP client adapter parse path.
• Adds focused unit coverage for metadata preservation on server and client adapters.

Issue Requirements

Requirement	Status
No linked issue requirement captured	N/A

Prior Findings Status

No prior human or inline review concerns were present in the supplied PR comment artifacts.

Blockers

No in-scope blocking findings remained after policy filtering.

Follow-up Findings

#	File:Line	Priority	Confidence	Suggestion
1	src/ouroboros/mcp/tools/subagent.py:198	Low	Medium	Existing comments still describe FastMCP metadata as dropped. They are now stale after this PR and should be updated in a follow-up to avoid misleading future changes.

Non-blocking Suggestions

| 1 | src/ouroboros/mcp/tools/evaluation_handlers.py:1469 | Documentation | Existing inline documentation says adapter metadata is dropped; this should be refreshed now that _to_fastmcp_tool_result() forwards _meta. |

Test Coverage Notes

• Reviewed added unit tests in tests/unit/mcp/client/test_adapter.py and tests/unit/mcp/server/test_adapter.py.
• Could not run pytest because this environment has no pytest module installed.
• Ran python3 -m py_compile on the changed source and test files successfully.

Design Notes

The change is well-scoped to MCP adapter translation boundaries. It keeps handlers thin and preserves internal MCPToolResult.meta without moving business logic into the server wrapper.

Design / Roadmap Gate

Affected boundary is MCP tool-result serialization/deserialization. Server-side MCPToolResult.meta is now mapped to SDK CallToolResult._meta, and client-side SDK meta is restored into internal MCPToolResult.meta. No persistence, replay, auth, or state-contract regressions were found in the changed paths.

Directional Notes

Maintainer memory emphasized keeping MCP handlers as thin unwrap/delegate/wrap layers; this PR follows that shape. I also checked the locked MCP SDK contract: direct CallToolResult returns with _meta are supported by FastMCP.

Test Coverage

• Reviewed added unit tests in tests/unit/mcp/client/test_adapter.py and tests/unit/mcp/server/test_adapter.py.
• Could not run pytest because this environment has no pytest module installed.
• Ran python3 -m py_compile on the changed source and test files successfully.

Merge Recommendation

Approve. No blocking runtime, API contract, or test-coverage issues were found in the current HEAD snapshot.

Review-Metadata:
verdict: APPROVE
head_sha: 261fd02
request_id: req_retry_exhausted_new_timeout_1779693693_1210
review_profile: memory-aware-zero-trust-v2
advisory_memory_only: true

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Reviewed by ouroboros-agent[bot] via Codex deep analysis